We have analyzed the pseudorapidity spectra of charged relativistic particles with β > 0.7 produced in Pb + Em (at energy 158 A GeV) reactions as a function of centrality. The relativistic nucleus ...beams were obtained from SPS machine. The number of g-particles (particles with 0.23 ≤ β ≤ 0.7) has been used to fix the centrality. We have applied the maximum entropy method to analyses the spectra and found some selected pseudorapidity values—nontrivial structure.
Simulation of the SCAN3 setup Afanasev, S. V; Dubinchik, B. V; Dryablov, D. K ...
International Journal of Modern Physics: Conference Series,
2015, Letnik:
39
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
The first results of the geometry GEANT3 simulation of the three-arm magnetic spectrometer SCAN3 are presented in this article. The possibility of detection of exotic nuclei (such as eta-mesic ...nucleus) with help of the SCAN3 and the Nuclotron internal target is shown.
η -nuclei in the SCAN experiment Michaličková, Katarína; Afanasiev, S.V.; Dryablov, D.K. ...
EPJ Web of Conferences,
2019, Letnik:
204
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
η
-mesic nucleus or the quasibound nuclear state of an
η
-meson in a nucleus is caused by the strong-interaction force alone. The project SCAN2 is aimed at searching and studying the
η
-meson nuclei ...production. The experiment is based on two-arms spectrometer using internal target at the Nuclotron. The setup was designed to study products from
η
-meson nucleus decay in the reaction
d
+
12
C → (A)
η
+
X
→
π
+
p
+ (
A –
2) at deuteron energies from 0:5 to 2:5 GeV/nucl. The energy spectrum of secondary protons has been measured. The dependence of the yields of protons and pions on the beam energy has been obtained. This dependence can show us the minimum energy for the
S
11
resonance formation. The first prototype of the neutron detector, which will be used in a new modified experimental setup SCAN3 for recording of neutrons from
η
-nucleus decays in the
πn
and
pn
channels, has been tested. The time-offlight method to obtain the neutron spectrum was used. The time resolution and efficiency of the neutron detector have been obtained.
The angular structures of particles produced in
208
Pb at 158
A
GeV/
c
and
197
Au at 11.6
A
GeV/
c
induced interactions with Ag(Br) nuclei in emulsion detector have been investigated. Nonstatistical ...well-ordered ring-like structures of produced particles in azimuthal plane of a collision have been found, and their parameters have been determined.
We have analyzed the behavior of different characteristics of hadron-nuclear and nuclear-nuclear interactions as a function of centrality to get a signal on the formation of intermediate baryon ...systems. We observed that the data demonstrate the regime change and saturation. The angular distributions of slow particles exhibit some structure in the above mentioned reactions at low energy. We believe that the structure could be connected with the formation and decay of the percolation cluster. With increasing the mass of colliding nuclei, the structure starts to become weak and almost disappears ultimately. This shows that the number of secondary internuclear interactions increases with increasing the mass of the colliding nuclei. The latter could be a reason of the disintegration of any intermediate formations as well as clusters, which decrease their influence on the angular distribution of the emitted particles.
Results on the coherent dissociation of relativistic
9
C nuclei in a nuclear track emulsion are described. These results include the charge topology and kinematical features of final states. Events ...of
9
C → 3
3
He coherent dissociation are identified.
The angular structures of particles produced in {sup 208}Pb-induced collisions with Ag(Br) nuclei in an emulsion detector at 158 A GeV/c have been investigated. Nonstatistical ringlike substructures ...in the azimuthal plane of the collision have been found and their parameters have been determined. An indication of the formation of ringlike substructures from two symmetrical emission cones, one in the forward and the other in the backward direction in the center-of-mass system, has been obtained. The ringlike substructures' parameters have been determined. The experimental results are in an agreement with I.M. Dremin's idea that the mechanism of the ringlike substructures' formation in nuclear collisions is similar to that of Cherenkov electromagnetic radiation.
A nuclear track emulsion was exposed to a mixed beam of relativistic
12
N,
10
C, and
7
Be nuclei having a momentum of 2 GeV/
c
per nucleon. The beam was formed upon charge exchange processes ...involving
12
C primary nuclei and their fragmentation. An analysis indicates that
10
C nuclei are dominant in the beam and that
12
N nuclei are present in it. The charge topology of relativistic fragments in the coherent dissociation of these nuclei is presented.
The results of investigation of the dissociation of the 2.86-A-GeV/c{sup 14}N nucleus in an emulsion are presented. The cross sections for various fragmentation channels are given. The invariant ...approach to analysis of fragmentation is used. The momentum and correlation characteristics of the {alpha} particles for the {sup 14}N {sup {yields}} 3{alpha} + X channel in the laboratory system and c.m.s. of three {alpha} particles are examined. The results obtained for the {sup 14}N nucleus are compared with similar data for the {sup 12}C and {sup 16}O nuclei.
Experimental data on fragmentation channels in peripheral interactions of
8
B nuclei in nuclear track emulsions are presented. A detailed analysis made it possible to justify selections of events of ...the electromagnetic-dissociation process
8
B →
7
Be +
p
and to estimate its cross section. Events of
10
C peripheral dissociation that were observed in the same exposure are described.
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